Lois McMaster Bujold is known for her series of space opera novels about Miles Vorkosigan, a crippled but intelligent protagonist who has been, variously, a military officer, a secret agent, commander of a mercenary fleet, diplomat... the list goes on.
The Curse of Chalion is, as far as I know, her first fantasy novel. [A reader points out that it isn't.] The crippled but intelligent protagonist is a military officer who gets employed as a diplomat, secret agent, secretary... you get the idea. A fun read, the plot isn't perfect but it's still a cut above most fantasy novels these days. At the very least, it isn't a rehash of the "small company has to get [item] to destroy [dark lord]" plot.